Improvement in differential pulley-blocks



B. F. WARREN.

Differential Pulley-Block.

Patented Feb. 16,1875.

THE GRAPHIC C0.PHOTO-UTH.39&41 PARK PLAGEJL! "Trrn STATES PATENT QFFICE.

BENJAMIN F. WARREN, OF FISHKILL, NEW YORK, ASSIGNOR OF ONE-HALF HISRIGHT TO DANIEL W. WARREN, OF NEWARK, NEW JERSEY.

IMPROVEMENT IN DIFFERENTIAL PULLEY-BLOCKS.

Specification forming part of Letters Patent No. 159,987, dated February16, 1875; application filed August 4, 1874.

To all whom it may concern:

Be it known that I, BENJAMIN F. WARREN, of Fishkill, in the county ofDutchess and State of New York, have invented a new and usefulImprovement in Differential Pulley- Blocks; and I do hereby declare thefollowing to be a full and clear description of the same, which willenable others to use my improved blocks.

This invention relates to an arrangement of the principal or drivingsheave in a case, which also contains two smaller wheels or rollers, onwhich the said driving-sheave rests, the small wheels having flanges,which fit into the grooves of the driving-sheave, and thereby keep thefall or rope in place in the said grooves, and at the same time thesmall wheels act as anti-friction supports for the driving-sheave, whichsustains the load. The conformation of the grooves and flanges of theabove-named wheels or sheaves are peculiarly adapted to the purpose forwhich they are employed, and form a part of the subjectmatter ofthisinvention. There are also guiderollers in the bottom part of thecase to guide the ropes in the proper position, as will be hereinafterdescribed.

The invention will be readily understood by reference to theaccompanying drawings, of which Figure I is a side elevation of one ofthe improved blocks, with a part of the case removed to show thearrangement of the operative parts. Figs. II and III show how the twofriction-wheels rotate in the face of the driving-sheave.

The case A sustains three journals, 1) c d, for the two guide-sheaves BB and the two antifriction wheels or sheaves O D. The two guide-sheavesB B are placed upon the common journal I), located in the lower centralpart of the case A, and slightly above this journal; and in the oppositesides of the case are located the two journals 0 d, the location of thesheaves G D being such that the lower part of the periphery of theprincipal or driving sheave E will rest on them when the parts areassembled. The sheave E has two grooves, e and 0, turned in itsperiphery, the diameter of the said sheave being larger in the groove 0than the diameter in e, in the usual manner of differential sheaves.These grooves are V-shaped, beveling toward the outside of the sheave.There are flat faces at each side of both of the rope-grooves of thesaid sheave E, which said flat faces form treads for the sheave to restupon on the peripheries of its two sustaining-sheaves,(] D. The saidsheaves G D have each a central flange that fits into its respectivegroove in the sheave E, to hold the rope in place therein, and also-twoflat faces at the sides of the said central flange, that serve as treadsfor the treads of the sheave E to rest upon.

The rope may be of any material usually employed to or adapted torunning rigging, anl will be reeved over the power-sheave E and therunning sheave G in the usual manner. The rope will be held in positionin the grooves of the sheave E, as above described, and will be furtherguided in its proper position in the upper block by the two guidesheavesB B and the stationary stops a, which are attached to the sides of thecase A, the said stops guiding the rope into the grooves of the saidsheaves B B.

The sheaves B B being upon a common axle, a portion of the front sheaveB is broken away in the drawing to disclose the sheave B behind it.

Having described my invention, I claim- In combination with the sheavesor wheels 0 D. case A, and guiding sheaves or wheels B and B, the loosesheave or pulley E, with grooves e e, substantially as and for thepurposes set forth and described.

BEN J F. WARREN.

Witnesses:

FRANKLIN BARRITT, Brennan GERNER.

